On very small projects, or when changes are made to an existing building, approval may be sought by giving a 'building notice'. In this case, a building inspector will approve the works as they are carried out by a process of inspection. However, generally, a ‘full plans’ application will be made, in which plans, specifications and calculations are submitted for approval before construction begins. Full plans approvals are also subject to inspection during the course of the works, typically during the construction of foundations, damp proof courses and drains and perhaps at other key stages, but the risk that problems will be found is much lower than it is with the building notice route.

A full plans approval notice is valid for three years from the date of deposit of the plans. This can be very important given the speed at which the regulations change, meaning that a building which has been approved, but not built may require re-design and further approval if the regulations are revised.

When the building is finished, it is important to ensure that a completion certificate is sought from the approving body as evidence that the completed works comply with the regulations.